During catheterization procedures, the introduction of guidewires, guide catheters or other instruments may stimulate an unwanted vasospasm, which creates narrowing of the blood vessel. Typical treatments are to wait for the vasospasm to relax, add a vasorelaxant such as nitroglycerine, or risk damage to the narrowed lumen of the vessel by continuing the procedure. Waiting for the spasm to resolve increases procedure time, and adding nitroglycerine may cause unwanted systemic effects of reducing blood pressure. There is thus a need to provide a means to treat vasospasms in an acute setting in a manner that is preferably immediate and local.